The use of a portable light source to power an additional electric device or module via a power takeoff from the power source of the portable light source is known for a number of applications.
Once example is the use of secondary lighting sources on a battery-powered flashlight or lantern. The secondary lighting source may provide an alternative type of light for the user or may provide a flashing, high-visibility light so that the user may be seen and/or located. One can certainly replace one light bulb for another in incandescent versions of such powered flashlights or lanterns. However, if the secondary light source requires replacement of its functional components, apart from a bulb, often times the flashlight or lantern is not configured for ready replacement or repair of the secondary light source.
Another example is in mining cap lamps. Such lamps are typically mounted on hard hats worm by miners to provide illumination in underground mine shafts. Such cap lamps are well known in the mining equipment industry and provide illumination while the miner's hands remain free to perform tasks. A cap lamp typically receives power from a battery power pack secured to the user's waist. Electrical wiring delivers power from the power pack to the lamp on the helmet. Normally, at the end of each working shift, the helmet and power pack are removed by the miner and the power pack is placed in a recharging device so that it is ready for use during a future shift.
Modern day mines often include a miner tracking system so that the location of miners may be tracked for safety purposes. Such systems often include sensors positioned throughout the mine shafts. A miner wears a radio frequency identification (RFID) tag which broadcasts a signal including the identity of the miner wearing the RFID tag. When the miner passes a miner tracking system sensor, the sensor receives the signal from the RFID tag. The sensors communicate with a central computer which tracks the location of miners wearing the RFID tags based on which sensors have received signals from the miners' RFID tags.
The RFID tags must receive electrical power to operate. Traditionally, wires have been soldered to the battery terminals of the cap lamp power pack and to the RFID tags so that the RFID tags receive power from the battery of the cap lamp power pack. A problem with such an arrangement, however, is that such modifications are time consuming and inconvenient. In addition, and more importantly, the quality of the soldered connections is often inconsistent which leads to reliability issues, especially in the harsh mining environment. The exposed wires of such a power takeoff are also exposed which makes them even more susceptible to damage.